The____isageneraldescriptionofthearchitectureofaworkflowmanagementsystemusedbytheWFMC,inwhichthemaincomponentsandtheassociatedinterfacesaresummarize D．Theworkflowenactmentserviceistheheartofaworkflowsystemwhichconsistsofseveral__请作答该选项__.
A.workflow engines
B.processes
C.workflow threads
D.tasks
正确答案是A